Crankcase blow-by exhauster



Dec. 1, 1964 -1.w.HUMPl-|REYS cRANKcAsE rBLOW-BY ExHAUsTER Filed May l0,1962 United States Patent O 3,159,150 CRANKCASE BLOW- Y EXHAUSTER .lohnW. Humphreys, Muskegon, Mich., assigner to Johnson Products, lne.,Muskegon, Mich., a corporation of Michigan Fiied May 10, 1962, Ser. No.193,797 6 Claims. (Cl. 12S-119) This invention relates to internalcombustion engines, and more particularly to a controlled exhaustingsystem for an engine crankcase.

This is an improvement of my invention in patent application, Serial No.167,562, filed January 22, 1962, now Patent No. 3,108,581 and entitledCrankcase Pressure Controller. Control of noxious fumes and vapor fromthe crankcase of internal combustion engines by conventionalvacuum-responsive regulators involves inherent control problems, sincethe desired rate of vapor ow must vary roughly inversely with the amountof manifold vacuum. This is because maximum vacuum occurs at periods oflow engine blow-by, and minimum vacuum occurs at periods of maximumblow-by. At full load operation of the engine, intake vacuum ispractically nil. Consequently, it is almost impossible to draw all ofthe crankcase gases through the regulator into the manifold, especiallyif the engine is somewhat Worn. Further, at all other loads it isnecessary to draw excess air through the flow system. With thesemanifold vacuum-responsive systems therefore, the crankcase must bevented to the atmosphere to allow exit of excess gases under maximumblow-by, low-vacuum conditions, and to allow excess air entry under highvacuum low blow-by conditions. Moreover, as is well known, each flowregulator device of the vacuum-type must be matched to the particularengine displacement to provide proper interrelated action between theindependently varying manifold vacuum and blow-by volume.

Thus, applicant devised the apparatus disclosed in the above identifiedpatent application to provide crankcase ventilation controlled bypressure of gases in the crankcase to regulate the iiow from thecrankcase to the intake system of the engine. Thereby, the iiow wasregulated in direct proportion to the positive crankcase pressure due toa flow Valve controlled by a pressure responsive element exposed to thecrankcase pressure on one side and to the atmosphere on the other side.Slight positive pressure variations in the crankcase govern the openingof the valve to provide a constant, accurate control.

It has been found that under some operating conditions, it is preferableto have a slight vacuum in the sealed crankcase, rather than the slightpositive pressure over atmospheric, but to still utilize Ia regulatorcontrolled by the crankcase pressure rather than the manifold vacuum.

It has been found that the pressure in the crankcase over atmospherictends to cause slight engine oil leakage past gaskets and bearings undersome operating conditions.

Therefore, it is an object of this invention to provide a crankcaseventilation regulation system, especially for a sealed crankcase,wherein the regulation is governed by the crankcase pressure, and thecrankcase is maintained at the pressure slightly below atmospheric.

It is Kanother object of this invention to provide a novel,crankcase-pressure controlled ventilation system wherein the controlvalve is operated in response to crankcase pressure, and includes aslight vacuum assist to open the valve when the pressure in thecrankcase exceeds a certain, predetermined pressure slightly belowatmospheric pressure.

It is another object of this invention to provide such a crankcaseexhausting system enabling the crankcase to be completely sealed to theatmosphere to prevent any undesirable exhausting of noxious vapors intothe at- Frice mosphere. The novel regulator causes the crankcasepressure to constantly seek a norm slightly below atmospheric pressure,thereby removing any tendency of blow-by gases from seeping out to theatmosphere or backing up through the engine. The regulator further needsno special calibration for different sized engines. It accommodates anyengine no matter what the displacement or age thereof. It is relativelysimple and inexpensive in construction and completely dependable inoperation. It neither utilizes nor needs any spring elements but ratheris capable of operation with a simple buttery valve and pressurediaphragm. It does not require excess air to be passed into the enginethrough the crankcase, and is extremely sensitive in operation. Itfurther is not conducive to collecting carbon deposits, since it isself-washing in nature.

Other objects and advantages of this invention will be apparent uponstudying the following specification and drawings in which:

`FIG. 1 is 'an elevational schematic View of an internal combustionengine embodying the invention;

FIG. 2 is an elevational, partially sectioned view of the novelapparatus;

FIG. 3 is an elevational view of the front of the apparatus; and

FIG. 4 is a sectional view of a suitable filler tube plug utilized withthis invention.

Basically, the invention comprises, in an engine assembly, a conduitmeans extending between the crankcase of the sealed internal engine andthe intake manifold means, and including a ow valve, preferably abutterfly valve, and a pressure responsive regulator member oper-ablylinked to the valve. One side of the pressure responsive member isexposed to atmospheric pressure, and the opposite side to crankcasepressure. The pivotal butteriiy valve is responsive to and regulated bycrankcase pressure. The valve includes a slight vacuum assist in itsopening action by having a slightly greater area on one side of itspivotal mounting responsive to the pressure differential between thecrankcase and the intake manifold tending to open the valve, than thearea on the opposite side of the pivot responsive to the differential ina manner tending to close the Valve. This is achieved by mounting thebutterfly in a slightly offset manner in the conduit with respect to thecenterline of the conduit.

Referring now to the drawings, in FIG. 1 is disclosed an internalcombustion engine 10 having a regulated crankcase ventilation system 12including a conduit portion 14 extending from the crankcase 16 of theengine, a regulator 18 and a conduit portion 20 extending between theregulator and the intake manifold 22 of the engine. Thus, conduits 14and 20, as well as the passageway 30 through regulator 18, form aconduit means adapted to conduct the vapors from the crankcase to theintake manifold. The crankcase of the engine is sealed to the atmospherein the preferred form of the invention by utilizing a suitable sealingcap 24 in the fllerspout 26 as illustrated in FIG. 4.

The regulator housing includes a lirst portion defining a passageway 30between conduits 14 and 20, and a second portion enclosing an annulardiaphragm 32. The diaphragm is sealingly secured at its outer peripheryand its inner central portion. The outer periphery is preferably securedby crimping edge 36 of the first generally pie-shaped sheet metal member38 over the peripheral edge of the facing pie-shaped member 40.Obviously, other equivalent means could be used. The inner portion ofthe diaphragm is secured between a pair of connected plates 42 and 44which are secured to link 46. Link 46 is in turn pivotallymounted tolever 48 which is connected onto shaft t) by squeezing the ears of lever48 together with a suitable screw 52.

A conduit portion 43 enables gaseous communication between conduitportion 14 from the crankcase 16, and one side of the diaphragm. A portoli enables communication between the atmosphere and the opposite sideof the diaphragm 32. A supplementary peripherally positioned port 62 mayalso be utilized if desired.

Shaft 5i! is offset from the centerline 66 through passageway 30.Butterfly valve disc 68 is mounted as by screws '70 to shaft 5d. Sincethe shaft is offset with respect to the circular passageway, the disc ismounted with a larger area on vone side of the shaft than on the other,i.e. on the left side of the shaft as compared to the right asillustrated in FIG. 2.

It will be noted that the disc pivots clockwise as illustnated in FlG. 2to open the passageway and pivots counterclockwise to close thepassageway, Thus, since the area of the disc on the left side of theshaft 50 is larger than the area on the right, the pressure differentialbetween the crankcase 16 and the intake manifold 22 will tend to assistthe butterfly disc to open, since it will tend to move it in a clockwisedirection.

As a consequence of these particular structural features, the basicregulatoiiy control of valve 68 is achieved by action of the pressureresponsive diaphragm 32 as determined by the differential pressurebetween crankcase pressure and atmospheric pressure. Since, however, thevalve disc has a slight vacuum assist, the pressure of the crankcasedoes not have to rise to that of atmospheric or slightly above in orderto open valve Vdisc ed. Rather, as'soon as the crankcase pressureapproaches a predetermined value, still slightly less than atmosphericpressure, the small amount of force due to the vacuum assist will causethe disc to open and the pressure responsive meinber 32 to move to allowflow between the crankcase and the intake manifold. The exact pressurebelow atmospheric at which the valve opens and which it tends to seekduring continuous operation is determined by the off-center position ofshaft Sil and the differential area between the two sides of thebutterfly valve 68. y By carefully controlling this offset condition,the differential force added will be made very small so that thecrankcase can be sealed to the atmosphere without buckling of the pan orother detrimental effects, while still maintaining a definite vacuum,i.e. sub-atmospheric pressure, in the crankcase. ln other words, theregulator is a crankcase pressure controlled regulator with a vacuumassist.

Certain obvious modifications may occur; to those in the art uponstudying the foregoing invention. Such obvious modifications are deemedto be part of this invention which is to be limited only by the scope ofthe appended claims and the reasonably equivalent structure to thosedefined therein.

I claim: n

l.-An engine assemblyV comprising: an internal combustion engineincluding a sealed crankcase and an intake manifold means; conduit meansextending between said crankcase and manifold means; flow regulatormeans for said conduit meansV including a iiow valve in saidconduitrmeans and a pressure responsive member having one side exposedto crankcase pressure and the other side exposed to atmosphericpressure; said pressure respon- .sive member being adapted to shift saidvalve generally in proportion to crankcase pressure; and said valveincluding a small, vacuum-assist, opening action by having a slight-lyVgreater area responsive to the pressure differential between thecrankcase and the intake manifold tending to open said valve than thearea responsivek to said differential tending :to close said valve.

'2. The apparatus in claim l wherein said valve comprises a butterflyvalve mounted in an off-center position in said conduit means.

3. The apparatus in claim l wherein said pressure responsive membercomprises a diaphragm operably linked to said valve and said valvecomprises a butterfly valve mounted in an olf-center position in saidconduit means.

4. A flow regulator means adapted to be mounted in a conduit meansbetween the crankcase and the intake manifold of an internal engine,comprising: a housing including a first portion having a passagewayadapted to communicate with the conduit means and a second portionadapted 4to house a pressure responsive member; a pressure responsivemember in said second portion eX- posed to the atmosphere on one sideand to the end of said passageway adaptedto communicate with thecrankcase on the other side; said pressure responsive member beingoperably linked to a valve member in said passagewaT and said valvemember having a slightly greater area adapted to be responsive to adifferential pressure across said valving member tending to operi saidvalving member when exposed to manifold vacuum and crankcase pressure,to assist the action of said pressure responsive member.

5. The apparatus in claim 4 wherein said valve member comprises abutterfly valve mounted in an olf-center position in said passageway.

6. The apparatus in claim 4 wherein said pressure responsive membercomprises a diaphragm operably linked to said valve and said valvecomprises a butterfly valve mounted in an otfenter position in saidpassageway.

References Cited in the le of this patent UNITED STATES PATENTS2,423,592 Foster July 8, 1947 2,775,960 Druzynski i Jan. l, 1957

1. AN ENGINE ASSEMBLY COMPRISING: AN INTERNAL COMBUSTION ENGINEINCLUDING A SEALED CRANKCASE AND AN INTAKE MANIFOLD MEANS; CONDUIT MEANSEXTENDING BETWEEN SAID CRANKCASE AND MANIFOLD MEANS; FLOW REGULATORMEANS FOR SAID CONDUIT MEANS INCLUDING A FLOW VALVE IN SAID CONDUITMEANS AND A PRESSURE RESPONSIVE MEMBER HAVING ONE SIDE EXPOSED TOCRANKCASE PRESSURE AND THE OTHER SIDE EXPOSED TO ATMOSPHERIC PRESSURE;SAID PRESSURE RESPONSIVE MEMBER BEING ADAPTED TO SHIFT SAID VALVEGENERALLY IN PROPORTION TO CRANKCASE PRESSURE; AND SAID VALVE INCLUDINGA SMALL, VACUUM-ASSIST, OPENING ACTION BY HAVING A SLIGHTLY GREATER AREARESPONSIVE TO THE PRESSURE DIFFERENTIAL BETWEEN THE CRANKCASE AND THEINTAKE MANIFOLD TENDING TO OPEN SAID VALVE THAN THE AREA RESPONSIVE TOSAID DIFFERENTIAL TENDING TO CLOSE SAID VALVE.